fexofenadine hcl 180 mg, desloratadine 5 mg and placebo in suppression of wheal and flare induced by histamine

Conditions: Allergic Rhinitis

Summary: to examine the relative potency, onset of action and duration of action of fexofenadine hcl 180 mg (allegra) and desloratadine 5 mg (clarinex) as compared to placebo on skin wheals and flares induced by histamine.


Eligibility criteria:
inclusion criteria: * male and female subjects, 12 to 55 years of age, may participate * positive histamine skin prick tests (or duplicate histamine skin prick test) with a summation flare (σf) greater than or equal to 20 mm larger than diluent control, and summation wheal (σw) greater than or equal to 6 mm larger than diluent control at the screening visit 1 * all female subjects must have a negative urine pregnancy test at the screening visit * female subjects who are sexually active will be expected to use one of the following birth control methods throughout the study (see section 4.4) * subjects must be within 15% of normal body weight for height or a bmi less than 29.9 (based on nhlbi guidelines) * subjects willing and able to adhere to visit schedules and all study requirements * all female subjects must have a negative urine pregnancy test at each treatment visit (visit 2, 4, and 6). * continues to meet all inclusion and exclusion criteria exclusion criteria: * asthma that requires treatment with medication other than an inhaled, short-acting beta agonist * signs and symptoms of currently active allergic disease (seasonal allergic rhinitis, perennial allergic rhinitis, episodic allergic rhinitis) * upper respiratory tract infection, sinusitis, asthma or flu-like symptoms within 2 weeks prior to visit 1 * subjects who have dermatographism or other skin conditions which might interfere with the interpretation of the skin test results * subjects who are receiving immunotherapy * any excessive amounts of alcohol (no more than two drinks/day on average) * any excessive use of caffeine (more than six cups of coffee per day or equivalent) * any use of tobacco/nicotine products within 90 days of visit 1 * any disease state or surgery known to affect the gastrointestinal absorption of drugs * known hypersensitivity to the investigational product or to drugs with similar chemical properties * subjects who will be visiting a tanning salon during the study * subjects who will need to use artificial tanning products during the study * night or variable shift workers during the study * pregnancy * breast-feeding * history of hypersensitivity to the study medications or to drugs with similar chemical structures * treatment with other h1-receptor antagonists in the last year before study entry * likelihood of requiring treatment during the study period with drugs not permitted by the clinical study protocol (see section 6.2) * treatment with any investigational product in the last 30 days before study entry * no person or child of a person directly associated with the administration of the study may participate as a study subject * clinically relevant cardiovascular, hepatic, neurologic, endocrine, or other major systemic disease making implementation of the protocol or interpretation of the study results difficult * mental condition rendering the subject unable to understand the nature, scope, and possible consequences of the study * subject unlikely to comply with protocol, e.g., uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study * use of any of the following drugs within the time indicated prior to the first dosing visit: